A New Method for Estimating Flow Duration Curves : an Application to the Burdekin River Catchment, North Queensland, Australia

This paper presents a new method of representing flow duration curves (FDC) using a logarithmic transformation. The FDC has been defined using two parameters – the ‘cease to flow’ point, and the slope of the FDC. This method for defining the FDC has been applied to 23 sub-catchments of the Burdekin River in North Queensland, Australia. The two parameters defining the FDC have been related to the area, mean annual precipitation, drainage density and total stream length of the catchments under consideration. Finally, a regionalisation procedure has been developed whereby the FDC for an ungauged catchment can be predicted based on the attributes of that catchment. Significant landuse change such as dam construction can have a significant impact on the FDC, implying that the FDC may be used as an indicator of landuse change in a catchment. Finally, the mirror-image nature of the FDC may imply that it is possible to predict high flows in a particular catchment based on analysis of low flows in that catchment.